Tubular coiled heat exchanger and device for manufacturing same

Abstract

A tubular coiled heat exchanger adapted for cooling or heating of various fluids in various fields of industry. The heat exchanger comprises a shell and a core around which tubes having essentially the same length are wound at least in two layers. The tubes may have grooves projecting into the tubes to intensify heat abstraction within the tubes. A member of a streamlined cross-section, such as, a wire, adapted for forming fins is wound around the tubes with a pitch of at least twice the diameter of the wire. The tubes are wound around the core so that the tops of the fins of each tube coil come alternately in contact with those of the fins and with tube surfaces of adjacent coils. The above embodiment of the heat exchanger makes it possible to vary the number of turns of the tubes when winding the tubes being set once without any distance pieces between the layers. This ensures the manufacture of a highly compact heat exchanger featuring high thermal and hydrodynamic properties. The heat exchanger may prove to be most advantageous in cryogenics, in plants for liquefaction and separation of natural gas in particular.

What we claim is: 
     
       1. A generally compact multilayer tubular coiled heat exchanger comprising: a core; tubes having essentially the same length and tightly wound around said core in at least two layers; streamlined finned members in the form of wire rods being wound around each of said tubes with a pitch of at least twice the thickness of said member; a shell mounted coaxially with said core and encompassing it; said tubes are adapted to pass a fluid therealong and therebetween in a space defined by said shell and said core, said tubes being wound around said core to form coils, so that the distances between the centers of the cross-section of tube coils in one layer and between the centers of the cross-sections of the same tube coils of said layer gradually vary from a value equal to the sum of the diameter of one of said tubes plus twice the height of a wire rod fin to a value equal to the sum of the diameter of said tube plus a single height of the wire rod fin, the above distance relationship periodically repeating over the entire length and cross-section of the heat exchanger; wherein the finned wire rod surfaces of each tube coil alternately contacts the finned wire rod surfaces and the tube surface of the adjacent tube coils and wherein the number of turns in the layers of a multilayer tubular coiled heat exchanger can be varied without the need for structure distant pieces between the tube layers. 
     
     
       2. A heat exchanger of claim 1, in which each of said tubes has on its external surface annular grooves running along the entire length of said tube and projecting into said tube. 
     
     
       3. A heat exchanger of claim 1, in which said member for making fins on each of said tubes has a streamlined cross-section.